Small-ring heterocyclic compounds containing phosphorus and arsenic hetero-atoms will be prepared to examine their potential reactivity and utility as alkylating agents. Pathways to marocyclic ligands containing phosphorus and arsenic donor sites will be explored, together with the coordination chemistry of the donors and related compounds. The objective here is to design chelating agents which show specificity for particular metal ions. The use of bulky ligands to stabilize group V compounds in unusual coordination or oxidation states will be studied. BIBLIOGRAPHIC REFERENCES: On the large difference between the diastereomeric 1J(P-P) values of 1, 2-bistrifluoromethyldiphosphine. J.P. Albrand, J.B. Robert, and H. Goldwhite, Tetrahedron Lett., 949 (1976). Structure and dynamic stereochemistry of a 5-coordinate spiroarsorane. H. Goldwhite, J. Grey, and R. Teller. J. Organometall. Chem. In press (1976).